Physical Activity and Cardiovascular Disease

Original Editor - Nadja Thöner

Top Contributors - Nadja Thöner, Laura Ritchie, Wendy Walker, Kim Jackson, Lucinda hampton, Admin, Vidya Acharya, Uchechukwu Chukwuemeka, Tarina van der Stockt, Rucha Gadgil, Lauren Lopez, 127.0.0.1, Evan Thomas, Michelle Lee and Adam Vallely Farrell

Definition

The cardiovascular system consists of the heart and blood vessels. There is a wide array of problems that may arise within the cardiovascular system eg. endocarditis, rheumatic heart disease, abnormalities in the conduction system.

Cardiovascular disease (CVD) or heart disease refer to the following 4 entities:

1. Coronary artery disease (CAD): Sometimes referred to as Coronary Heart Disease (CHD), results from decreased myocardial perfusion that causes angina, myocardial infarction (MI), and/or heart failure. It accounts for one-third to one-half of the cases of CVD.
2. Cerebrovascular disease (CVD): Including stroke and transient ischemic attack (TIA)
3. Peripheral artery disease (PAD): Particularly arterial disease involving the limbs that may result in claudication
4. Aortic atherosclerosis: Including thoracic and abdominal aneurysms

Early recognition of risk factors and primary prevention have significantly decreased the morbidity and mortality associated with CAD. Lifestyle modification with diet, exercise, and smoking cessation is crucial to reduce cardiovascular risk factors.

Physical activity very beneficial for CAD risk reduction. Even a little is better than nothing.

• At least 150 minutes per week of moderate-intensity activities and greater than 75 minutes a week of vigorous-intensity physical activities are helpful.
• Moderate activities include brisk walking (2.4 to 4 mph), biking (5 to 9 mph), active yoga, and recreational swimming, whereas vigorous activities include jogging/running, biking (greater than 10 mph), playing tennis, swimming, etc.
• Moving from being totally sedentary to an activity level of approximately 72.2 minutes per week—a little over 10 minutes per day, also improves cardiorespiratory fitness.

Physical Activity Effects on Cardiovascular Diseases

The benefits of exercise with 1000kcal per week in secondary prevention decreases the all-cause mortality around 20-30%  Physical activity improves systolic blood pressure, angina symptoms and exercises tolerance in patients without re-vascularisation . For patients with re-vascularisation physical activity improves the quality of lives and exercise tolerance, as well as 29% of cardiac events and around 20% lower readmission rates.

A large and rigorous systematic review and meta-analysis, published in June 2018, found that "Resistance Training leads to improvement in cardiac autonomic control of diseased individuals"; interestingly, this review also demonstrated that in people with no cardiac disease Resistance Training has "no or minimal effects on cardiac autonomic control of healthy individuals".

However, it is important to note that only current physical activity is protective – sports participation in youth does not provide protection in later life unless activity is maintained.

PA Effect on Hypertension/Blood Pressure

Studies show that there is an inverse relationship between physical activity and the incidence of hypertension, with inactive individuals having a 30-50% greater risk of high blood pressure/hypertension than fit and active individuals.

The frequency of exercise has a significant effect: the acute effect of PA causes a reduction in blood pressure lasting 4 to 10 hours; therefore, daily activity may achieve clinically significant improvement,

Aerobic fitness training has the greatest benefit, but dynamic resistance and isometric resistance at moderate intensity training have smaller benefits.

Exercise in Coronary Artery Disease

The evidence for the benefit of exercise in Coronary Artery Disease (CAD) is compelling and it has been conclusively established that exercise is indicated in the primary and secondary prevention of CAD. Studies demonstrate that the benefits of exercise are greater than the results of PCI (Percutaneous Coronary Intervention) techniques.

In one study of 101 men with stable CAD, over a two year period, regular exercise intervention outperformed PCI on all measures:

• "Event free survival" rates after 24 months were 78% in the exercise group versus 62% in the PCI cohort (P = 0.039).
• At two years, maximal oxygen consumption (VO₂max) had increased by 10% in the exercise group versus 7% in the PCI group.
• Inflammatory markers improved in the exercise cohort: high-sensitive C-reactive protein levels and interleukin-6 levels were significantly reduced after two years of exercise by 41 and 18%, respectively, whereas no relevant changes were observed in the PCI group.

PA in Secondary Prevention of MI

Guidelines on secondary prevention for patients following a myocardial infarct recommend:

• Following MI, patients should be physically active for 20-30 minutes a day to the point of slight breathlessness.
• People who are not active to this level should increase their activity gradually aiming to increase their exercise capacity. They should start at a level that is comfortable, and increase the duration and intensity of activity as they gain fitness. 

Exercise in Chronic Heart Failure

The benefits of physical exercise in patients with Chronic Heart Failure (CHF) have been identified in many studies and in a large meta-analysis published in 2006, the authors came to the following conclusions:

• exercise training in stable patients with mild to moderate CHF results in statistically significant improvements in maximum heart rate, maximum cardiac output, peak VO₂, anaerobic threshold, 6 minute walk test and HRQL (quality of life questionnaire).

Symptoms of Cardiovascular Events

The classic symptoms of a cardiovascular event include;

• Chest discomfort (pressure, squeezing, fullness, pain)
• Discomfort in one or both arms, back, jaw or stomach
• Shortness of breath
• Cold sweat
• Nausea
• Lightheadedness

Women may not experience the classic symptoms above. Instead, they are more likely to experience the following;

• Unusual fatigue
• Sleep disturbances
• Weakness
• Shortness of breath
• Nausea/vomiting
• Back or jaw pain.

The American Heart Association designed a Healthy Heart Quiz: Are you able to recognise a Heart Attack? They have also produced a useful graphic on this topic.

Prodromal Symptoms

A 10mmHg decrease in systolic blood pressure was associated with a higher risk for fatal and non-fatal cardiovascular events. Increased long-term variability in systolic blood pressure was associated with a higher risk for cardiovascular events, mortality and disease.

Exercise Prescription

The American College of Sports Medicine (ACSM) published guidelines which were based on their traditional exercise guidelines but adapted for the physiological differences in patients with CAD compared to healthy individuals. Patients with CAD should perform everyday physical activity as well as supervised exercise lessons.

Mode

• Continuous exercise using large muscle groups (e.g. walking, swimming, group aerobics) fosters cardiovascular endurance. Upper extremity exercises (e.g. using an arm ergometer) may be useful for people with musculoskeletal problems in their lower extremities.
• Resistance exercises should be provided in a circuit training approach. 10-12 exercises using 10-12 repetitions with sufficient resistance that can be performed comfortably. Cross-training is possible as well.

Frequency

• A minimum of three non-consecutive days per week
• With the increased frequency of exercise, the risk of musculoskeletal injuries increases

Duration

• 10 minute warm-up and cool-down phases, including stretching and flexibility exercises.
• 20-40 minute continuous or interval cardiovascular exercise. Interval training may be useful for people with peripheral vascular disease and intermittent claudication.

Intensity

Cardiovascular exercise in supervised programs should be of moderate intensity. Intensity can be determined using various methods;

• 40-85% VO₂ max
• 40-85% maximal heart rate reserve (HR_max - resting heart rate) X 40-85% + resting heart rate
• 55-90% of HR_max
• The Rating of Perceived Exertion (RPE) is appropriate to monitor exercise intensity

Progression

• Slow progression of exercise duration and intensity

Monitoring

• Patient observation
• Measure heart rate and rhythm
• Measure blood pressure when clinically indicated (depending on the patient-specific risks for exercise-related complications)
• Patients who exercise without direct supervision should exercise at a lower intensity

Contraindications for Exercises

Patients should exercise at a sub-symptom threshold to avoid provoking myocardial ischaemia, significant arrhythmias or symptoms of exercise intolerance. Patients at higher risk should exercise at lower levels of intensity.

Absolute contraindications to exercise;

• Uncontrolled or poorly controlled asthma
• Cancer or blood disorders when treatment or disease cause leukocytes below 0.5 x10/L, haemoglobin below 60g/L or platelets below 20 x 10/L
• COPD: Patients are required to be stable before training and oxygen saturation levels should be above 88-90%.
• Diabetes if blood glucose is >13 mmol/L or <5.5 mmol/L
• Patients with diabetic peripheral or autonomic neuropathy or foot ulcers should avoid weight bearing exercise
• Any diabetic with acute illness or infection
• Heart disease - acute myocardial infarction or unstable angina until stable for at least 5 days, dyspnoea at rest, pericarditis, myocarditis, endocarditis, symptomatic aortic stenosis, cardiomyopathy, unstable or acute heart failure, uncontrolled tachycardia
• Hypertension - resting blood pressures of a systolic >180mmHg or diastolic >100mmHg or higher should receive medication before regular physical activity with particular restrictions on heavy strength conditioning, which can create particularly high pressures
• Osteoporosis - avoid activities with a high risk of falling
• Fever - should be settled to avoid a risk of developing myocarditis
• Unexplained dizzy spells
• Acute pulmonary embolus or pulmonary infarction
• Excessive or unexplained breathlessness on exertion
• Any acute severe illness

Special Considerations

Antihypertensive medication can influence exercise and should be considered by the therapist when prescribing exercise.

• Beta Blockers decrease exercise capacity because it creates a ceiling effect, meaning it will not allow the heart rate rise beyond a certain point. Thus the target heart rate for monitoring should not be used. Rather let the patient use the rate of perceived exertion (RPE) or calculate the target heart with a graded stress test while the patient is using the medication.
• Vasodilators, alpha - and calcium channel blockers may lead to a sudden blood pressure drop while exercising or afterwards.
• Proper warming up and cooling down will help improve the blood pressure response to exercise
• Educate patients to avoid the valsalva manoeuvre during resistance training

Risk of Exercises

Risk of Exercise for patients with coronary heart disease: acute myocardial infarction, cardiac arrest and sudden death. Incidence in supervised cardiac rehabilitation programs are:

• 1 myocardial infarction per 294,000 patient hours
• 1 cardiac arrest per 112, 000 patient hours
• 1 death per 784,000 patient hours.

Over 80% of persons who reported cardiac arrest symptoms while exercising have been successfully resuscitated with prompt defibrillation .

Exercises and Medications

Exercise response to cardiac medications

Resources

• CVD News and Research Updates (The Heart and Stroke Foundation South Africa)
• Measuring Physical activity Intensity https://www.cdc.gov/physicalactivity/basics/measuring/ http://www.who.int/dietphysicalactivity/physical_activity_intensity/en/ Exercise Testing
• The Motivate2Move website, created by Wales Deanery, has a useful section on activity and cardiorespiratory health.